Exotropia

EXOTROPIA

Definition

• Divergent misalignment of the visual axis
• Concomitant
  • Congenital exotropia
  • Intermittent exotropia
  • Sensory exotropia
  • Consecutive exotropia
• Incomitant
  • 3 rd nerve palsy

Epidemiology

• Less common than esotropia;
• Exact etiology unknown;
• Most common form is intermittent exotropia.

Congenital exotropia

• Presents before age 6 months;

• Large-angle constant exotropia (>35 prism diopters);

• Often associated with neurologic impairment or craniofacial disorders;Z

• Amblyopia uncommon

• These children usually alternate fixation;

• The refractive error is similar to that of the general population;

• Treatment: Surgery early in life.

accomidative

Intermittent exotropia

• The most common divergent strabismus in childhood;

• Onset usually before age 5;

• Deviation becomes manifest during times of visual inattention, fatigue, or stress;

• Exposure to bright light often causes a reflex closure of one eye;

• Amblyopia is uncommon.

Nonsurgical treatment:

• Corrective lenses are prescribed for significant refractive errors
  • Myopia, astigmatism, and hyperopia >+4.00D;
• Additional minus lens power (overminus spectacles) to stimulate accomodative convergence to help control;
• Alternate daily patching;
• Active orthoptic treatment to improve fusional convergence amplitudes (if convergence insufficiency);
• Base-in prisms.

1/2 time of day without durgical, if more surgical

Surgical treatment:

• Surgery for increased tropic phase, poor recovery of fusion once tropic .
• Bilateral lateral rectus recession;
• 3 or 4 muscle surgeries for large deviation.

Straight eyes

Exotropicospe

Sensory exotropia

• Due to vision loss or long-standing poor vision in one eye;
• Children younger than 5 with unilateral vision loss may develop ET or XT; adults and older children usually develop XT;
• Angle of deviation may be variable and usually increases with time.

Consecutive exotropia

• Exotropia that follows previous strabismus surgery for esotropia;
• Surgery depends on many factors:
  • Size of deviation;
  • Type and amount of surgery that preceded its development;
  • Presence of duction limitation;
  • Lateral incomitance;
  • Level of visual acuity in each eye.

3rd nerve palsy

SYMPTOMS

• Drooping of eyelid
• Binocular double vision(Diplopia)
• Outward deviation of the eye.

SIGNSZ

• Ptosis
• Abduction of the globe (Exotropia)
• Intortion of the globe which increases on attempted downgaze
• Limitation of adduction &Elevation & Depression
• Dilated pupil (pupil involving lesion)

#OSPE. -

• 1
• 2 - divergent extropia
• 3
• 4
• 5 - ptosis -
• 6
• 7
• 8
• 9 left 3rd nerve palse

Z aptotis + divergent = exo - 3rdn aptosis+ myosis = horners

pupil affect 3rd n p